The present invention relates generally to starter mechanisms for internal combustion engines, and particularly to such engines designed for marine use and having reversing transmissions.
In conventional outboard marine motors, it has been possible in some cases to initiate engine starting operation when the transmission is in gear. For several reasons, including operator and passenger safety, this characteristic is undesirable. Thus, various mechanisms have been devised for preventing the starting of the engine when the transmission is in gear. Such prior art starter interlook mechanisms are disclosed in U.S. Pat. No. 3,866,591 to Burmeister et al., U.S. Pat. No. 4,167,929 to DuBois, and U.S. Pat. No. 4,534,739 to Slattery. In operation, such prior systems have been found to be less than ideal in terms of production cost, ease of assembly, and/or reliability.
Another such prior mechanism employs a cable operated lock-out system to prevent unsafe starting of the engine. However, a significant drawback of this system is that when the starter housing must be removed for service, the cable system remains attached to the engine by the cable. Thus, the cable system cannot be easily removed from the engine and impedes service operations.
A further drawback of conventional shift interlock systems is that the lock-out system must be assembled onto the starter housing after the starter housing has been mounted to the engine. This results in a complicated and awkward assembly procedure, especially in a mass-production situation.
Thus, there is a need for a shift interlock system for a marine engine which is simple in operation, economical to produce, is reliable, and permits easy disassembly for engine maintenance.